<!DOCTYPE html>
<html lang="en">
<head>
  <meta charset="UTF-8">
  <meta name="viewport" content="width=device-width, initial-scale=1.0">
  <title>定位</title>
</head>
<body>
  <!-- 
    position:
      1. static
      2. relative
      3. absolute
      4. fixed
      5. sticky
    z-index
   -->
</body>
</html>